Fish Bowl? (Patreon)

Looking through an observation port at a diving pool at Tokyu Vacations Hotel on Miyako Island. While something like this is often associated in our minds with bikini-clad submerged babes smiling and happily waving their hands, a more practical use is for beginners' scuba diving classes. (Unless Saver chooses to draws characters for us, like he did for the diving boat banner at the top...)